Exhibit 31.2 CERTIFICATION
OF CHIEF FINANCIAL OFFICER I, Ernest J. Mrozek, certify that: 1. I have reviewed this report on Form 10-Q of The
ServiceMaster Company; 2. Based on my knowledge, this report does not contain
any untrue statement of a material fact or omit to state a material fact
necessary to make the statements made, in light of the circumstances under
which such statements were made, not misleading with respect to the period
covered by this report; 3. Based on my knowledge, the financial statements,
and other financial information included in this report, fairly present in all
material respects the financial condition, results of operations and cash flows
of the registrant as of, and for, the periods presented in this report; 4. The registrants other certifying officers and I
are responsible for establishing and maintaining disclosure controls and
procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting
(as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have: (a) Designed such disclosure controls and procedures,
or caused such disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the registrant,
including its consolidated subsidiaries, is made known to us by others within
those entities, particularly during the period in which this report is being
prepared; (b) Designed such internal
control over financial reporting, or caused such internal control over
financial reporting to be designed under our supervision, to provide reasonable
assurance regarding the reliability of financial reporting and the preparation
of financial statements for external purposes in accordance with generally
accepted accounting principles; (c)
Evaluated the effectiveness of the registrants disclosure controls and
procedures and presented in this report our conclusions about the effectiveness
of the disclosure controls and procedures, as of the end of the period covered
by this report based on such evaluation; and (d)
Disclosed in this report any change in the registrants internal control over
financial reporting that occurred during the registrants most recent fiscal
quarter (the registrants fourth fiscal quarter in the case of an annual
report) that has materially affected, or is reasonably likely to materially
affect, the registrants internal control over financial reporting; and 5. The registrants other certifying officers and I
have disclosed, based on our most recent evaluation of internal control over
financial reporting, to the registrants auditors and the audit committee of
registrants board of directors (or persons performing the equivalent
functions): (a) All significant deficiencies and material
weaknesses in the design or operation of internal control over financial reporting
which are reasonably likely to adversely affect the registrants ability to
record, process, summarize and report financial information; and (b) Any fraud, whether or not material, that involves
management or other employees who have a significant role in the registrants
internal control over financial reporting. Date: August 2, 2006 By:
/s/ Ernest J. MrozekErnest J. MrozekPresident and Chief Financial Officer 37